scholarly journals Extraction and Application of Natural Rutin From Sophora japonica to Prepare the Novel Fluorescent Sensor for Detection of Copper Ions

2021 ◽  
Vol 9 ◽  
Author(s):  
Shilong Yang ◽  
Lu Sun ◽  
Zhiwen Song ◽  
Li Xu
Keyword(s):  
Inclusion Complex ◽  
Emission Intensity ◽  
Copper Ions ◽  
Fluorescent Sensor ◽  
Fluorescent Sensors ◽  
Emission Peak ◽  
The Novel ◽  
Buffer Solution ◽  
Sophora Japonica ◽  
Fluorescent Emission

Rutin (R), a representative flavonoid found in various biomasses, can be used to prepare different fluorescent sensors for environmental, biological and medical fields. In this work, the natural R in Sophora japonica was extracted and purified to prepare fluorescent-responding sensor systems intended to recognize copper ions with both strong selectivity as well as appropriate sensitivity. Results showed that neat R had no obvious fluorescent emission peak in PBS buffer solution. However, when R and (2-hydroxypropyl)-β-cyclodextrin (CD) were introduced within buffer solution, fluorescent emission intensity was significantly increased due to the resultant R-CD inclusion complex. In addition, the formed R-CD inclusion complex was shown to behave as the aforementioned fluorescent sensor for copper ions through a mechanism of quenched fluorescent emission intensity when R-CD became bound with copper ions. The binding constant value for R-CD with copper ions was 1.33 × 106, allowing for quantification of copper ions between the concentration range of 1.0 × 10–7–4.2 × 10–6mol⋅L–1. Furthermore, the minimum detection limit was found to be 3.5 × 10–8mol⋅L–1. This work showed the prepared R-CD inclusion complex was both highly selective and strongly sensitive toward copper ions, indicating that this system could be applied into various fields where copper ions are of concern.

scholarly journals Rapid and simultaneous purification of aflatoxin B1, zearalenone and deoxynivalenol using their monoclonal antibodies and magnetic nanoparticles

2021 ◽  
Author(s):  
Hyuk-Mi Lee ◽  
Hwan-Goo Kang
Keyword(s):  
Monoclonal Antibodies ◽  
Magnetic Nanoparticles ◽  
Aflatoxin B1 ◽  
Animal Feed ◽  
Immunoaffinity Chromatography ◽  
The Novel ◽  
Buffer Solution ◽  
Purification Method ◽  
Recovery Rates ◽  
Single Spike

AbstractTo develop a new simple and simultaneous purification method for mycotoxins in feeds and grains, magnetic nanoparticles (MNPs) conjugated with monoclonal antibodies (mAbs) against mycotoxins were used to separate aflatoxin B1 (AFB1), zearalenone (ZEA) and deoxynivalenol (DON). For a single spike of each mycotoxin into the buffer solution (16% MeOH in PBS), mean recoveries were 93.1–95.0% for AFB1 (5–20 ng/mL spiked), 87.2–96.0% for ZEA (125–500 ng/mL spiked) and 75.2–96.9% for DON (250–1,000 ng/mL spiked) by HPLC and ELISA. Recoveries of AFB1 (20 ng/mL) and ZEA (500 ng/mL) simultaneously spiked into the buffer solution were 87.0 and 99.8%, respectively. Recovery rates of AFB1/DON and DON/ZEA spiked simultaneously were 86.2%/76.6% and 92.0%/86.7%, respectively, at concentrations of 20 ng/mL AFB1, 500 ng/mL ZEA, and 1,000 ng/mL DON. Recoveries using the novel mAb–MNP conjugated system in a buffer solution simultaneously spiked with AFB1, ZEA and DON were 82.5, 94.6 and 73.4%, respectively. Recoveries of DON in animal feed were 107.7–132.5% at concentrations of 250–1,000 ng/g spiked in feed. The immunoaffinity chromatography (IAC) clean-up method was compared with the purification method using novel mAb–MNP. After fortification of animal feed with AFB1 (5, 10 and 20 ng/g feed) and ZEA (125, 250 and 500 ng/g feed), AFB1 and ZEA were purified using both the methods. In the case of the novel mAb-MNP conjugated system, mean recoveries for AFB1 were 89.4, 73.1 and 88.3% at concentrations of 5, 10 and 20 ng/g feed, respectively. For ZEA, mean recoveries were 86.7, 85.9 and 79.1% at concentrations of 125, 250 and 500 ng/g, respectively. For IAC purification, recoveries were 42.9–45.1% for AFB1 and 96.8–103.2% for ZEA. In conclusion, the present purification method using monoclonal antibodies conjugated to MNPs can be used for simple and simultaneous purification of mycotoxins from feed and maize.

Bacteriophage conjugated IRMOF-3 as a novel opto-sensor for S. arlettae

2016 ◽  
Vol 40 (9) ◽  
pp. 8068-8073 ◽  
Author(s):  
Neha Bhardwaj ◽  
Sanjeev K. Bhardwaj ◽  
Jyotsana Mehta ◽  
Manoj K. Nayak ◽  
Akash Deep
Keyword(s):  
Fluorescent Sensor ◽  
Sensitive Detection ◽  
The Novel

This article reports the novel assembly of a bacteriophage-based fluorescent sensor for the selective and sensitive detection of a model bacterium ‘Staphylococcus arlettae(S. arlettae)’.

Development of highly selective fluorescent sensors for detection of glycolipids in vesicles and visualization of glutamate for neuronal imaging

2020 ◽  
Author(s):  
◽  
Ming Xu
Keyword(s):  
Fluorescence Enhancement ◽  
Chemical Sensor ◽  
Fluorescent Sensor ◽  
Hydrophobic Effect ◽  
Fluorescent Sensors ◽  
Nucleophilic Aromatic Substitution ◽  
Sensor System ◽  
Aromatic Substitution ◽  
Glutamate Binding ◽  
A Cell

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI-COLUMBIA AT REQUEST OF AUTHOR.] Fluorescent sensors are very useful tools for exploring chemical biology and advanced medical research. Herein, we propose four different fluorescent sensor systems for the recognition of some important biological molecules. The first sensor system is a multi-component fluorescent sensor complex for the sensing of glycolipids. The glycolipid sensor system is a novel design that takes advantage of supramolecular self-assembly. Results show that it can bind with both the sugar headgroup and hydrocarbon tail of glycolipids, and turn on the fluorescence of the sensor system. The second sensor is a cell-impermeable fluorescent sensor system for the recognition and extraction of glycolipids from vesicles. To avoid the fluorescence enhancement caused by the hydrophobic effect from cell membrane, we designed a series of cell-impermeable sensor complexes. In addition, these complexes were fully explored by vesicle studies. Another fluorescent sensor is NS600 which was developed for detecting and imaging glutamate in neurons. This sensor system that utilizes a nucleophilic aromatic substitution for glutamate binding, and produces a 270-fold fluorescence enchantment upon glutamate binding. Also, it overcomes drawbacks of previous glutamate sensors including low signal response and poor sensitivity. It enables a clear and accurate visualization of glutamate in cultural neurons. The last sensor is NS570, a cell-impermeable glutamate sensor which could be loaded into synaptic vesicles by vesicle cycling. This sensor is a reversible chemical sensor that gives a 2600-fold fluorescence enhancement upon the titration with glutamate and can be used to monitor the release of neuronal glutamate in real time.

Biochemical and Biophysical characterization of the main protease, 3-chymotrypsin-like protease (3CLpro), from the novel coronavirus disease 19 (COVID-19)

2020 ◽  
Author(s):  
Juliana C. Ferreira ◽  
Wael M. Rabeh
Keyword(s):  
Antiviral Drug ◽  
Analytical Techniques ◽  
The Novel ◽  
Buffer Solution ◽  
Biophysical Characterization ◽  
Main Protease ◽  
Wide Ph Range ◽  
The Stability ◽  
Ph Range ◽  
Novel Coronavirus

Abstract Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is responsible for the novel coronavirus disease 2019 (COVID-19). An appealing antiviral drug target is the coronavirus 3C-like protease (3CLpro) that is responsible for the processing of the viral polyproteins and liberation of functional proteins essential for the maturation and infectivity of the virus. In this study, multiple thermal analytical techniques have been implemented to acquire the thermodynamic parameters of 3CLpro at different buffer conditions. 3CLpro exhibited relatively high thermodynamic stabilities over a wide pH range; however, the protease was found to be less stable in the presence of salts. Divalent metal cations reduced the thermodynamic stability of 3CLpro more than monovalent cations; however, altering the ionic strength of the buffer solution did not alter the stability of 3CLpro. Furthermore, the most stable thermal kinetic stability of 3CLpro was recorded at pH 7.5, with the highest enthalpy of activation calculated from the slope of Eyring plot. The biochemical and biophysical properties of 3CLpro explored here will improve the solubility and stability of 3CLpro for optimum conditions for the setup of an enzymatic assay for the screening of inhibitors to be used as lead candidates in the drug discovery and antiviral design for therapeutics against COVID-19.

A 96-well Microfiltration Assay for Measurement of Total Clottable Fibrinogen

1999 ◽  
Vol 81 (02) ◽  
pp. 264-267 ◽  
Author(s):  
A. Keller ◽  
S. Argirion ◽  
D. L. Heene ◽  
C. E. Dempfle
Keyword(s):  
Clinical Trials ◽  
Protein Concentration ◽  
The Novel ◽  
Plasma Samples ◽  
Clotting Time ◽  
Buffer Solution ◽  
Clinical Routine ◽  
Vacuum Suction ◽  
Time Determination ◽  
Method R

SummaryIn clinical routine use, fibrinogen is measured by clotting-time methods, or by clot turbidity in photometric prothrombin time determination. For calibration of these assays measurement of total thrombinclottable protein has been recommended. We have now developed a microfiltration assay for total thrombin-clottable protein. Plasma samples were mixed with thrombin in a 96-well microfiltration device. After clot formation, the fluid was extracted by vacuum suction, and fibrin adherent to the filter membranes washed with buffer. Membrane segments with adherent fibrin were recovered from the 96-well manifold with a punch and transferred to tubes containing denaturing buffer solution. After dissolution of fibrin, protein concentration was determined by optical absorption at 280 nm. The microfiltration assay displayed a high correlation with the total clottable protein method (R = 0.95), and fibrinogen antigen (r = 0.96). Correlation with clotting time assays, and PT-derived fibrinogen in 150 clinical plasma samples was in the range of r = 0.84 to r = 0.97. Intraassay and day-to-day variability of the assay was comparable to the conventional total clottable fibrinogen assay. The novel microfiltration assay appears to be well suited for measurement of large series of samples for calibration, screening purposes, and clinical trials.

Two-Photon Ratiometric Fluorescent Sensor Based on Specific Biomolecular Recognition for Selective and Sensitive Detection of Copper Ions in Live Cells

2013 ◽  
Vol 85 (24) ◽  
pp. 11936-11943 ◽  
Author(s):  
Yan Fu ◽  
Changqin Ding ◽  
Anwei Zhu ◽  
Zifeng Deng ◽  
Yang Tian ◽  
...  
Keyword(s):  
Copper Ions ◽  
Fluorescent Sensor ◽  
Sensitive Detection ◽  
Live Cells ◽  
Biomolecular Recognition ◽  
Two Photon

scholarly journals Fluorescent Sensors Based on Organic Polymer-Capped Gold Nanoparticles for the Detection of Cr(VI) in Water

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Na Wang ◽  
Liangchen Wang ◽  
Hong Yang ◽  
Tingting Xiong ◽  
Shangping Xiao ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Redox Reactions ◽  
Inner Filter Effect ◽  
Potential Method ◽  
Fluorescent Sensors ◽  
Organic Polymer ◽  
Buffer Solution ◽  
Ph Values ◽  
Internal Electron ◽  
Interference Study

“Turn-off” fluorescent sensors for Cr(VI) have been fabricated based on organic polymer-capped gold nanoparticles. The fluorescence intensity, as well as the response behavior of the sensors, is dependent on the pH values of buffer solution and dilution amounts of the sensors. When diluted 50 times with pH 2.0 buffer solution, the sensors show good linear responses toward Cr(VI) at concentrations between 2.8–5.9 μM and 5.9–29 μM. The calculated detection limit is 0.63 μM (S/N=3). The interference study and real sample assays exhibit satisfying selectivity and reliability results. Furthermore, the quenched intensity of fluorescence could be recovered by Fe(II) ion, which provides a potential method to detect Fe(II) ions. The quenching and recovering mechanisms have also been investigated. It is suggested that the quenching mechanism is based on the combined effects of internal electron transfer and the inner filter effect. Finally, the recovering mechanism is based on the redox reactions between the Cr(VI) and Fe(II) ions.

scholarly journals Which is a better fluorescent sensor: aggregation-induced emission-based nanofibers or thin-coating films?

2020 ◽  
Vol 1 (4) ◽  
pp. 574-578
Author(s):  
Yexin Ding ◽  
Weili Li ◽  
Fangming Wang ◽  
Hongkun Li ◽  
Shengyuan Yang ◽  
...  
Keyword(s):  
Fluorescent Sensor ◽  
Fluorescent Sensors ◽  
Thin Coating ◽  
Coating Films ◽  
Aggregation Induced Emission

Aggregation-induced emission (AIE)-based fluorescent nanofibers (FNFs) and thin-coating films (FTFs) are employed as visual fluorescent sensors, and their performance dynamics is compared.

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